1. Field of the Invention
The present invention relates to a lock for doors, windows or the like, which comprises a case housing a control mechanism consisting of electric drive means for actuating at least one control rod acting upon one or a plurality of locking members.
This invention is applicable more particularly in the field of building hardware.
Various types of locks are already known which correspond to the above definition and are characterized in that they comprise a plurality of bolts for locking the door or window leaf at several levels against the dormant frame of the door or window.
2. The Prior Art
Thus, among these known locks, casement-bolts are well-known which comprise essentially at least one control rod extending upwards and/or downwards from a case housing the control mechanism transmitting the movement from a control handle actuated by the user to said control rods. On the other hand, the control rods of these known locks are provided with locking members such as rollers engaging in the locking position registering keepers disposed along the dormant frame.
Casement-locks are also known which are characterized by the addition, in comparison with simple casement-bolts, of a key-actuated member so that a locking bolt can be actuated for locking the control rods in their locking position. Thus, by preventing the movement of these control rods through a direct actuation of the locking members, as would normally be the case if a burglar attempted to break in, these casement-locks provide a higher degree of safety.
Casement-bolts, like casement-locks, are generally fitted in a cavity formed in the front edge of the leaf, the control rods being adapted to slide in a groove formed for this purpose and covered by a face plate.
Among these known devices having a plurality of locking points there are also multi-bolts locks which differ from the above-mentioned locks on the one hand by their position since they are secured to the inner side of the leaf. Under these conditions, the control mechanism as well as the control rods are in many instances concealed by a section member extending substantially throughout the height of the leaf. On the other hand, these multi-bolt locks are provided with locking members consisting for example of a dead bolt movable in a direction at right angles to the front stile of the leaf and parallel thereto.
The advantage offered by these locking devices secured to the inner side of the leaf, in comparison with the aforesaid casement-bolts or casement locks, lies in the fact that the various mechanical component elements are eventually reinforced appreciably, thus improving the leaf strength when a blow is applied thereto.
Recent technical improvements made in both electronic and electro-mechanical fields permit of motorizing one or the other function of the mechanism of the above-defined locks, so that this function can be remote-controlled.
This feature permitted inter alia of centralizing the control of a plurality of locking devices and eventually of opening and closing a plurality of doors, windows or the like in a building.
Thus, various means have been developed for motorizing these locks. In a first, well-known construction, an electric motor is associated with a lock bolt for locking the control rods in their locked condition. Simultaneously, resilient return means have been incorporated in the control mechanism for causing the automatic translation of said control rods to their locking position when closing the leaf.
In fact, this arrangement is a rather hybrid one since only the locking of the door, window or the like can be obtained automatically, the unlocking thereof requiring a manual intervention.
Another known proposition consists of a lock of which only the locking members are motor-driven.
This type of construction, though permitting the remote control of both the locking and unlocking of the door, window or the like, involves the use of as many motor means as there are locking members. Thus, these locking means are particularly expensive to manufacture, and furthermore the failure of a single motor would prevent the opening of the door or window.
Another known solution consisted in actuating the control rods by means of a single electric motor, the control rods being locked in their operative or locking position by electromechanical or electronic means.
In all the above-mentioned solutions the locks are constructions so complicated that the failure of a single mechanical, electromechanical or electronic element will prevent the locking or unlocking of the door, window or the like, Now, one can imagine that in case of fire or other disaster, the failure of such locks would cause people to be trapped in the house and not rescued in time.
A first attempt to palliate this inconvenience consisted in doubling the electric control means by using manual control devices. The obvious consequence of..this solution was an increased complexity of the equipment, without inasmuch providing a satisfactory answer to the question. In fact, a risk was still pending, in that the failure of the electric motor means might be followed by a failure of a mechanical component element as a consequence, for instance, of the distortion of the door, window or the like under the pressure of the crowd trying to reach the exit. In this case, no efficient and simple solution is available.